Inhaled nitric oxide (iNO) is used as a therapeutic gas to produce vasodilatory effect on patients. When inhaled, NO acts to dilate blood vessels in the lungs, improving oxygenation of the blood and reducing pulmonary hypertension. Because of this, nitric oxide is provided in inspiratory breathing gases for patients with various pulmonary pathologies including hypoxic respiratory failure (HRF) and persistent pulmonary hypertension (PPH). The actual administration of iNO is generally carried out by its introduction into the patient as a gas along with other normal inhalation gases. Such administration must be added in synchrony with the respiration pattern of the patient.
Magnetic resonance imaging (MRI) is a medical imaging technique used to visualize internal structures of a patient's body in detail. The MRI device utilizes large, powerful magnets in its operation. The very high strength of the magnetic field created by an MRI device can cause “missile-effect” accidents, where ferromagnetic objects are strongly attracted to the magnet resulting in danger to the patient and clinicians. To reduce the risks of projectile accidents, ferromagnetic objects and devices are typically prohibited in proximity to the MRI device and patients undergoing MRI examinations are required to remove all metallic objects. The safety of the patient and/or MRI device can be compromised by magnetically induced displacement forces and torque, Radio Frequency (RF) and gradient-induced heating/voltages/vibration, unintentional output and operational inhibition (device malfunction), etc. MRI compatibility issues, such as materials causing MR image artifacts or decreases in the MR image quality, can lead to diagnostic errors (inaccuracies/misinterpretations), significant lack of information and difficulties with follow-up exams.
During the management of HRF and PPH in neonates and adults it is often necessary to conduct imaging studies wherein iNO treatment is used in conjunction with head cooling procedures, measurement of cardiac shunting, and the measurement of pulmonary blood flow. While computed tomography (CT) scans are currently the mainstay for these procedures, concerns about exposure to CT-based radiation has been increasing, particularly for neonates. As a result, many clinicians would prefer to use MRI for conducting imaging in neonates. However, current nitric oxide delivery devices are not compatible for use in the high magnetic environment of a magnetic resonance imaging machine and therefore, it is currently not possible to deliver nitric oxide to a patient situated in an MRI suite. Moreover, abrupt or premature discontinuation of iNO treatment can result in rebound hypertension, which may result in adverse events as serious as death.
Therefore, there is a need for a device and method to allow for the safe administration, monitoring and display of the NO concentration to a patient situated in a MRI suite.